When states began using an expanded Department of Homeland Security system to check noncitizen voter rolls this year, it was supposed to legitimize the Trump administration’s efforts to leverage data from across federal agencies to catch voter fraud and strengthen immigration enforcement.
DHS recently incorporated sensitive data from the Social Security Administration on hundreds of millions more people into a tool known as the Systematic Alien Verification for Entitlements (SAVE) system. With the added information, the system can now perform bulk searches using Social Security numbers for the first time.
But the initial results didn’t exactly support President Donald Trump’s claims that non-referendum voting was widespread. Texas identified 2,724 “potential noncitizens” on its rolls, about 0.015% of the state’s 18 million registered voters. In Louisiana, 390 people were found out of 2.8 million registered voters, for a probability of about 0.014%.
Rather, experts say a sweeping data-sharing agreement that gives DHS the power to integrate Social Security data into SAVE could lead to errors that threaten Americans’ privacy and disenfranchise legitimate voters.
Previously unreported details of the agreement include surprisingly few guardrails to ensure accuracy and few details about how data will be kept secure, election and privacy lawyers who reviewed the agreement say. Additionally, there is no express prohibition on DHS deploying SSA data for other purposes, such as immigration enforcement.
Experts have expressed similar concerns about other parts of the Trump administration’s data pool push, which has sought to tap all kinds of traditionally tightly controlled federal information and even tax data.
Until this year, SAVE only included information about immigrants who had contact with DHS and were assigned an immigration identification number, such as permanent residents. State and local officials typically used the system to verify the status of immigrants when they applied for benefits such as SNAP, and to verify that each person registering to vote was a citizen.
Under a May 15 data-sharing agreement recently posted on the Social Security Administration’s website, the system added information, including full Social Security numbers, about millions of Americans not in the DHS database. The combined dataset combines this information with address, date of birth, criminal history, and immigration history.
The agreement allows SSA data to be used for searches to confirm the citizenship of voters and for “other authorized inquiries from federal, state, territorial, tribal, and local government agencies seeking to verify or confirm the citizenship or immigration status of individuals within their jurisdiction.”
When conducting these searches, SAVE stores not only the voter data uploaded by election officials, but also the results of the queries, according to data-sharing agreements and other documents from U.S. Citizenship and Immigration Services, the division of DHS that oversees SAVE. The document does not explain who can access this information or how it can be used.
Experts say adding Social Security data to SAVE could help election officials confirm whether voters are U.S. citizens en masse, but it should not be used to definitively determine that people are not.
That’s because multiple audits and analyzes show that citizenship information in SSA is often outdated or incomplete, especially for people who have become naturalized citizens. With the 2026 midterm elections about a year away, Karen Short, legal and research director for the League of Women Voters of America, said she is concerned that expanding the use of SAVE could lead to errors.
“The Trump administration is hunting people down to remove legally registered people from the rolls, and they’re doing it by looking at old, unreliable data,” Short said.
Multiple privacy lawyers said they believe it would be illegal for DHS to expand its use of SAVE without taking steps required by federal law, such as issuing a system of record notice to inform the public how the additional data will be collected, stored and used. Last month, advocacy groups sued the federal government, charging that its expansion of SAVE and other data integration efforts violates the Privacy Act, a federal law that prohibits public agencies from misusing personal information.
U.S. Citizenship and Immigration Services officials declined to answer questions from ProPublica.
In a filing in response to the advocacy group’s lawsuit, federal officials said a separate law, the Illegal Immigration Reform and Immigrant Responsibility Act of 1996, explicitly allows for the sharing of information to determine citizenship, making government agencies more cautious in determining whether a voter is a noncitizen.
“There is zero reason to believe that state officials have any interest in haphazardly and illegally removing large numbers of Americans from voter rolls, and there is no credible evidence that such a thing has ever happened or will happen in the near future,” the filing said.
Still, Leland Dudek, who served as acting SSA administrator until early May, told ProPublica that he cannot trust DHS to accurately flag noncitizens as the agency attempts to cross-reference data and files from multiple systems.
“They’re probably going to make a big mistake,” he said.
This summer, the Justice Department began requesting access to states’ voter registration lists, saying it was necessary to ensure compliance with the federal Voter List Maintenance Act. The agency is filing lawsuits against many states that don’t respond.
Some states that refuse to provide personal voter information directly to the Justice Department have agreements with DHS to upload the same information to the SAVE system.
A growing number of states are entering into agreements with DHS to use SAVE to vet voter rolls, according to documents obtained by the ACLU, which sued the administration over SAVE-related records. Ten states had signed such agreements for 2025. Ten more people had signed on as of July, the document said.
Naomi Gilens is an attorney at Protect Democracy, a nonprofit voting rights organization, specializing in issues related to privacy and technology. Gilens said it’s important for Americans to think about whether they want their government, not just this one but future ones, to provide them with more integrated information about them.
“This is a very invasive picture that begins to paint in one place the private lives of all the individuals who live here,” she says.
USCIS told NPR that as of last month, Homeland Security officials had cast more than 33 million voters through SAVE. So far, authorities have refused to speak publicly about the outcome of these investigations.
But the initial results are hidden in another document obtained by the ACLU.
As of late August, approximately 96.3% of voters checked by the SAVE system were identified by the system as U.S. citizens. For an additional 3.1% of voters, the system either could not find them or needed more information to determine their citizenship status. The system found that about 0.5% of voters checked were dead. and 0.04% appeared as non-nationals.
A copy of the 12-state agreement with DHS obtained by the ACLU and reviewed by ProPublica requires election officials to take additional steps to verify the SAVE results of voters whose systems identify them as non-U.S. citizens. Then, if SAVE still cannot confirm citizenship, election officials “must contact the registrant or registered voter to obtain proof of citizenship.”
Dudek and Kathleen Romig, a former Social Security official who now works at the Center on Budget and Policy Priorities, worry that even such measures won’t be enough to prevent discrepancies from occurring.
People’s names may be misspelled or listed differently in different datasets. Many states collect partial, rather than full, Social Security numbers from voters, and matches using partial numbers are even less accurate because many people share the same name, Dudek and Romig said.
“If you have a Jane Smith who is a citizen and a Jane Smith who is not, you don’t want to disenfranchise Jane Smith who happens to be a citizen,” Romig said.
Federal authorities have not yet added data to SAVE. Next up is passport information from the State Department, according to a recent USCIS presentation to election officials shared with ProPublica. (The State Department referred ProPublica’s request for comment to the Department of Homeland Security, which did not respond.)
